Answer: D
Explanation:
Because velocity is speed
H2O means water, which is made of two hydrogen and one oxygen atoms.
Oxygen is a gas that your body needs to function. Oxygen comes from the air.
Answer:
Food and cell type
Explanation:
Kingdoms are by far the most basic legal structure for living objects. Living objects are classified into realms depending on how they consume food, the kinds of cells that produce their bodies, and the total type of tissue in their bodies.
Birds use the magnetic fields and some fish i believe as well and maybe butterflies im not entirely sure <span />
The alkali metals are first column, alkali earth 2nd, halogens 2nd to last, and noble gases last. Hope it helps!